Method for manufacturing a chip package, a method for manufacturing a wafer level package, a chip package and a wafer level package

ABSTRACT

A method for manufacturing a chip package is provided. The method includes forming a layer over a carrier; forming further carrier material over the layer; selectively removing one or more portions of the further carrier material thereby releasing one or more portions of the layer from the further carrier material; and adhering a chip including one or more contact pads to the carrier via the layer.

TECHNICAL FIELD

Various embodiments relate generally to a method for manufacturing achip package, a method for manufacturing a wafer level package, a chippackage and a wafer level package.

BACKGROUND

Chips may be arranged regularly together in panel form or wafer form,e.g. in a reconstituted wafer form, in a chip package formation such asin embedded wafer level ball grid array (eWLB). A metal layer, which maybe designated as a redistribution layer (RDL), may serve as anelectrical connection to external connection pads. An embedded waferlevel package, e.g. embedded wafer level ball grid array (eWLB) may haveseveral associated problems, significant parts of which may beattributed to the mold compound. Problems may include warpage,deformation, e.g. x-y deformation, outgassing from the material,problems with the temperature cycling on board (TCoB) cyclingdurability, poor thermal conductivity, and difficulties associated withcontacts, e.g. backside of the ICs leads to contact.

SUMMARY

Various embodiments provide a method for manufacturing a chip package,the method including forming a layer over a carrier; forming furthercarrier material over the layer; selectively removing one or moreportions of the further carrier material thereby releasing one or moreportions of the layer from the further carrier material; and adhering achip including one or more contact pads to the carrier via the layer.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. The drawings are not necessarilyto scale, emphasis instead generally being placed upon illustrating theprinciples of the invention. In the following description, variousembodiments of the invention are described with reference to thefollowing drawings, in which:

FIG. 1 shows a method for manufacturing a chip package according to anembodiment;

FIGS. 2A to 2G show a method for manufacturing a chip package accordingto an embodiment;

FIG. 3 shows a method for manufacturing a wafer level package accordingto an embodiment;

FIG. 4 shows a method for manufacturing a chip package according to anembodiment;

FIG. 5 shows a chip package according to an embodiment;

FIG. 6 shows a chip package according to an embodiment; and

FIG. 7 shows a method for manufacturing a chip package according to anembodiment;

FIGS. 8A to 8D shows a method for manufacturing a chip package accordingto an embodiment.

FIG. 9 shows a chip package according to an embodiment.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration”. Any embodiment or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs.

The word “over”, used herein to describe forming a feature, e.g. alayer, “over” a side or surface, may be used to mean that the feature,e.g. the layer may be formed “directly on”, e.g. in direct contact with,the implied side or surface. The word “over”, used herein to describeforming a feature, e.g. a layer “over” a side or surface, may be used tomean that the feature, e.g. the layer may be formed “indirectly on” theimplied side or surface with one or more additional layers beingarranged between the implied side or surface and the formed layer.

Various embodiments provide a method for carrying out reconstitution ofa wafer and/or panel.

Various embodiments provide an embedded wafer level package which maynot require a mold compound.

Various embodiments provide a reconstituted wafer, wherein integratedcircuit chips may be arranged precise and/or elastically and/or planarlyin cavities of a metal sheet and/or foil and/or plate.

Various embodiments provide an embedded wafer level package which mayinclude a metal sheet and/or metal foil and/or metal plate, e.g.including copper and/or stainless steel, in which cavities may bestructured in the metal sheet and/or foil and/or plate, wherein thecavities may be slightly larger than the integrated circuit (IC) chipsto be mounted. The metal sheet and/or metal foil and/or metal plate maybe structured by etching or sandblasting, and cavities which result fromthe structuring may be at least partially filled with glue, e.g.conductive glue, a solder material or a paste.

According to various embodiments, an etch stop layer may be used toprecisely form the cavities in the metal sheet and/or metal foil and/ormetal plate, and the etch stop layer may also be used as an adhesion foradhereing the IC chips to the metal sheet and/or metal foil and/or metalplate.

FIG. 1 shows method 100 for manufacturing a chip package according to anembodiment. Method 100 may include:

forming a layer over a carrier (in 110);

forming further carrier material over the layer (in 120);

selectively removing one or more portions of the further carriermaterial thereby releasing one or more portions of the layer from thefurther carrier material (in 130); and

adhering a chip including one or more contact pads to the carrier viathe layer (in 140).

FIGS. 2A to 2G show method 200 for manufacturing a chip packageaccording to an embodiment.

Method 200 may include forming layer 202 over carrier 204 as shown in210 of FIG. 2A. Carrier 204 may include an electrically conductivesheet. Carrier 204 may include an electrically conductive foil. Carrier204 may include an electrically conductive plate. Carrier 204 mayinclude a metal. Carrier 204 may include at least one material from thefollowing group of materials, the group consisting of: copper, nickel,iron, silver, gold, palladium, copper alloy, nickel alloy, iron alloy,silver alloy, gold alloy, palladium alloy. For example, carrier 204 mayinclude CuFe2P, e.g. carrier 204 may include CuFe01P. Carrier 204 mayinclude a leadframe material. Carrier 204 may include stainless steel.Carrier 204 may include a thickness ranging from about 50 μm to about1000 μm, e.g. about 100 μm to about 800 μm e.g. about 100 μm to about300 μm. Carrier 204 may include, but is not limited to including, thefollowing dimensions. Carrier 204, if in circular or round form, mayhave a diameter of e.g. about 200 mm, or about 300 mm, or about 450 mm.Carrier 204, if in rectangular or square form, may have alength×breadth, for example of 200 mm×200 mm, or 300 mm×450 mm, or450×600 mm. These dimensions of the carrier may depend on the equipment.

Layer 202 may be formed over carrier 204 and further carrier material206 may be formed over layer 202. Layer 202 may function as an etch stoplayer, e.g. a protective layer for carrier 204 during etching of furthercarrier material 206. Layer 202 may further function as an adhesionlayer to adhere further carrier material 206 to carrier 204.Furthermore, layer 202, in addition to functioning as an etch stoplayer, and as an adhesion layer between further carrier material 206 andcarrier 204, may also function as a support for a die attach material,which adheres chip to carrier 204. Therefore, it may be understood thatlayer 202, described herein may not only include a single layer, and mayaccording to various other embodiments include more than one layer, e.g.a multi-layer arrangement, in order to fulfill the functions describedabove.

Layer 202 (single layer or multi-layer) may function as part of anadhesion for adhering further carrier material 206 to carrier 204, as anetch stop protective layer for carrier 204, and eventually as anadhesion for a chip to carrier 204. Layer 202 according to variousembodiments is shown in FIGS. 8A to 8E and will be described further indetail below.

Layer 202 may include a thickness ranging from about 1 μm to about 50μm, e.g. about 10 μm to about 40 μm, e.g. about 15 μm to about 35 μm. Itmay be understood that these thicknesses may depend on the material oflayer 202 and the deposition methods used to deposit layer 202. Further,these thicknesses may depend on roughness of carrier 204. Thesethicknesses may be described further below. Layer 202 may have as far aspossible a uniform thickness.

Generally, layer 202 may be deposited by at least one method from thefollowing group of methods, the group of methods consisting of:electroplating, electroless plating, galvanic deposition, lamination,foil lamination, sputtering, evaporation, chemical vapor deposition,plasma enhanced chemical vapor deposition, spin-coating, spraying. Thesemethods may be selectively used for deposition of single layer 202 orfor multi-layers of layer 202.

Depending on whether an electrically conductive connection is requiredbetween a chip back side (shown later) and carrier 204, materials forlayer 202 may be chosen accordingly. For example, according to variousembodiments, layer 202 may include an electrically conductive material.According to other embodiments, layer 202 may include an electricallyinsulating material, e.g. an electrically insulating layer. It may beunderstood that a logic chip may allow for either an electricallyinsulating die attach or an electrically conductive die attach, whereasa power semiconductor chip with electrical backside contact may onlyallow for an electrically conductive die attach. Therefore, if chip 218includes a logic chip, then in addition to the functions describedabove, layer 202 may provide an electrical insulation or an electricalpath between the chip adhered side and carrier 204. If chip 218 includesa power semiconductor chip, then an electrically conductive connectionbetween a side of chip 218 adhered to carrier 204 and carrier 204 may berequired by layer 202. Therefore, layer 202 may be selected and/orprocessed according to the requirements of the chip package.

FIG. 8A shows part layer 202 arrangement according to variousembodiments.

According to an embodiment, layer 202 may include a single electricallyconductive layer. Layer 202 may include, for example, a single solderlayer 202A, which may be deposited for example by galvanic deposition.Layer 202 as a solder layer 202A may function as soldering attach layerbetween further carrier material 206 and carrier 204. In subsequentprocesses, solder layer 202A may function as an etch stop layer. It maybe understood that after etching, intermetallic phases, which may beunsuitable for re-melting, e.g. Cu—Sn interfaces, may be formed onsolder layer 202A, and an adhesive layer (described later) may bedeposited subsequently to provide an attachment, e.g. by adhesion orsintering, between a chip and carrier 204.

According to another embodiment, instead of a solder layer 202A, layer202 may include a single layer of electrically conductive glue 202B.Electrically conductive glue 202B may function as an adhesion layerbetween further carrier material 206 and carrier 204, and further as anetch stop layer. After etching, an additional adhesive layer mayoptionally be required for adhering a chip to carrier 204 via singlelayer 202B.

According to another embodiment, layer 202 may include single layer202C. As an example, layer 202C may include nanopaste, e.g. a silvernanopaste, which may function as a sintering attachment layer betweenfurther carrier material 206 and carrier 204, and further as an etchstop. Sintering layer 202C may need to be further processes later, orsubsequent processes may need to be carried out to ensure that a chipmay be adhered to carrier 204 via single sintering layer 202C. Suchfurther processes may include formation of an adhesion layer, e.g.comprising electrically conductive glue or solder, or electricallyconductive paste, over sintering layer 202C.

FIG. 8B shows layer 202 arrangements according to various embodiments.According to an embodiment, layer 202 may include an electricallyinsulating glue 202D. Electrically insulating glue layer 202D mayinclude an electrically insulating material, e.g. including at least onematerial from the following group of materials, the group consisting of:polyimide, benzocyclobuten (BCB), epoxy. Electrically insulating gluelayer 202D may be formed over carrier 204 by at least one method fromthe following group of methods, the group of methods consisting of: spincoating, spraying, printing, lamination.

Electrically insulating glue layer 202D may function as at least one ofan etch stop layer, an adhesion for adhering further carrier material206 to carrier 204, and further as a die attach for adhering a chip tocarrier 204.

In particular, polyimide may fulfill all three functions, by curing,e.g. for adhering further carrier material 206 to carrier 204, as anetch stop, and then reheating, e.g. for adhering a chip to carrier 204.

FIG. 8C shows part of a chip package according to an embodiment.According to various other embodiments, layer 202 may include amulti-layer. According to the embodiment, an optional electricallyconductive layer 202E may be formed between carrier 204 and at least oneof layers 202A, 202B or 202C.

It may be understood that according to various embodiments, thedifferent types of layers 202A, 202B, 202C, 202D may be combined, orused individually or in combination with other layers, to form layer 202arrangement which may serve the functions of an adhesion layer betweenfurther carrier material 206 and carrier 204, as an etch stop layer forcarrier 204 and as an adhesive between a chip and carrier 204.

In reference further to process 210, after deposition of layer 202 overcarrier 204 according to a process described with respect to at leastone of FIGS. 8A to 8D, further carrier material 206 may be formed overlayer 202.

Further carrier material 206 may include a thickness ranging from about60 μm to about 200 μm, e.g. about 80 μm to about 180 μm, e.g. about 100μm to about 150 μm. Further carrier material 206 may include the samematerial or different material as carrier 204.

Generally, further carrier material 206 may be deposited by at least onemethod from the following group of methods, the group of methodsconsisting of: lamination, sintering, gluing or printing. Layer 202materials may be taken into account when selecting a deposition methodfor further carrier material 206.

According to various embodiments, further carrier material 206, mayinclude a layer, e.g. a foil, such as a copper foil, which may belaminated and/or sintered to layer 202.

For example, if layer 202 includes as a top-most layer, layer 202C whichincludes a nanopaste, such as silver nanopaste, then further carriermaterial 206 may be sintered to sintering layer 202C of layer 202.

According to another embodiment, for example, if layer 202 includes as atop-most layer, layer 202B or layer 202D which includes glue, thenfurther carrier material 206 may be adhered, e.g. glued, to carrier 204by a glue, e.g. via electrically insulating glue layer 202D orelectrically conductive glue 202B of layer 202.

According to an embodiment, for example, if layer 202 includes as atop-most layer solder layer 202A, further carrier material 206 may besoldered to carrier 204 by a solder layer, e.g. solder layer 202A oflayer 202.

According to various embodiments, it may even be possible that insteadof forming layer 202 and further carrier material 206 in separateprocesses, layer 202 and further carrier material 206 may be formedtogether over carrier 204. For example, layer 202 and further carriermaterial 206 may form part of a single foil, e.g. a resin coated copper(RCC) foil, which may be adhered, e.g. laminated, to carrier 204. Thefoil may include the resin, which includes an electrically insulatinglayer and copper coating, i.e. 206. In which case, layer 202 togetherwith further carrier material 206 may be formed simultaneously overcarrier 204 by foil lamination (See FIG. 8D).

According to various embodiments, it may even be possible that layer 202may be deposited over further carrier material 206, for example,according to similar methods as described in process 210, before forminglayer 202 and further carrier material 206 over carrier.

According to various other embodiments, further carrier material 206 maybe joined or adhered to carrier 204 by a roll-to-roll process,particularly where high volumes are required. A portion of a roll offurther carrier material 206 may be joined to a further portion of aroll of carrier 204 via layer 202, which may be deposited, e.g. viaspraying, between carrier 204 and further carrier material 206.According to various embodiments, it may even be possible that layer 202may be deposited over further carrier material 206, for example,according to similar methods as described in process 210, before forminglayer 202 and further carrier material 206 over carrier.

Method 200 may include selectively removing one or more portions 208 offurther carrier material 206 thereby releasing one or more portions 212of layer 202 from further carrier material 206 as shown in 220 of FIG.2B. One or more portions 208 of further carrier material 206 may beselectively etched, wherein layer 202, which may include at least one oflayers 202A, 202B, 202C, 202D, 202E, may function as an etch stop layer.In other words, layer 202 may prevent etching of carrier 204, i.e. mayprotect carrier 204 from being etched, by being selectively resistant tothe etchant used for etching further carrier material 206. One or moreportions 208 of further carrier material 206 may be selectively removedby at least one method from the following group of methods, the group ofmethods consisting of: chemical etching, sandblasting. Sandblasting inparticular may used when layer 202 includes a glue. In other words,layer 202 may be resistant to these methods for selectively removing oneor more portions 208.

One or more portions 212 of layer 202 released from further carriermaterial 206 may be commonly joined by further portions 214 of layer 202covered by further carrier material 206. In other words, furtherportions 214 may be covered by portions of further carrier material 206not removed by the selective removal process. The removed one or moreportions 208 may be slightly larger than the size of the chips 218 to beplaced within the one or more portions 208. It may be understood thatthe removal of one or more portions 208 may be referred to as aformation of one or more cavities 208 in the stacked carrier 204-layer202-further carrier material 206 arrangement.

It may be understood that in addition to one or more cavities 208 beingformed, other holes 908 may also be formed in further carrier material206 during the etching process (See FIG. 9). Holes 908 may be smallerthan cavities 208 and may be used for forming an electrical connection956 in hole 908 through further carrier material 206 to carrier 204.

Following etching, intermediate processes may be carried out on releasedone or more portions 212 of layer 202 if required, to adhere a chip tocarrier via layer 202. Depending on layer 202 and on etching materials,released one or more portions 212 of layer 202, may or may not be ableto function as a chip adhesion material after etching.

In the case that layer 202 may not be able to function as a chipadhesion material, adhesion layer 216 may be formed over layer 202. Inother cases, portions of layer 202 may be removed. For example, if layer202 includes a single layer e.g. a polyimide foil 202D, it may be thecase that portions of layer 202D may be removed. Optionally, as shown inFIG. 9, portions of layer 202D which may be exposed by the formation ofcavity 208 may be removed, and furthermore, portions of layer 202Dexposed by the formation of hole 908 may also be removed. The removalmay be carried out, e.g. using back-sputtering if layer 202D is thin ore.g. lasering. Subsequently, an adhesion layer 216, e.g. electricallyconductive glue or solder or nanopaste, may be formed over carrier 204in cavity 208, for example by printing. Later on, further electricallyconductive material 956 may be formed in hole 908 to form an electricalconnection 956 through further carrier material 206 to carrier 204. Itmay be understood that through etching, besides removing one or moreportions of further carrier material 206, it may also be possible toselectively remove one or more portions of carrier 204. In other words,one or more portions of at least one of carrier 204 and further carriermaterial 206 may be selectively removed. It may be understood that atleast one of carrier 204 and further carrier material 206 may even bestructured such that at least one may include an electrically conductiveredistribution layer, for example if layer 202 includes an electricallyinsulating layer.

Adhesion 216 may be an electrically conductive glue and/or soldermaterial and may be deposited in cavities 208. Adhesion layer 216 may beselected such that a chip 218 may be adhered to carrier 204 via layer202 and adhesion layer 216.

Chip 218 may be adhered to carrier 204 by a range of methods, e.g.soldering, diffusion soldering or adhesive bonding.

For soldering, e.g. diffusion soldering, adhesion layer 216 may includea solder material including at least one material from the followinggroup of materials, the group consisting of: silver, silver alloy, lead,copper, tin, tin alloy.

If adhesive bonding is used, adhesion layer 216 may include anelectrically conductive material, e.g. an electrically conductiveadhesive. Adhesion layer 216 may include for example, epoxies, polymerswith electrically conductive particles, e.g. gold, silver, copperparticles. For example, adhesion layer 216 may include an electricallyconductive material including at least one material from the followinggroup of materials, the group consisting of: an electrically conductiveglue, an electrically conductive adhesive, an electrically conductivepolymer, an electrically conductive organic polymer, an electricallyconductive epoxy. Furthermore, adhesion layer 216 may be screen printedonto layer 202.

For a non-electrically conductive adhesion, adhesion layer 216 mayinclude an electrically insulating material, e.g. an adhesive, e.g. aglue, including at least one material from the following group ofmaterials, the group consisting of: a polymer, an organic polymer,epoxy. If layer 202 already includes electrically insulating material202C, e.g. durimide polyimide, e.g. benzocyclobuten, then adhesion layer216 may not be necessary, as electrically insulating material 202C maybe used both as an etch stop as well as an adhesive glue between thechip and carrier 204.

Adhesion layer 216 may be formed over one or more portions 212 of layer202 released from further carrier material 206, i.e. within one or morecavities 208 of the stacked carrier 204-layer 202-further carriermaterial 206 arrangement. Challenges of print in cavities may beovercome by printing developments and sliced squeegees. Adhesion layer216 may not be limited to having a particular thickness, but accordingto various embodiments may have a thickness ranging from about 3 μm toabout 70 μm, e.g. about 15 μm to about 60 μm, e.g. about 20 μm to about40 μm. Adhesion layer 216 may be deposited over by at least one methodfrom the following group of methods, the group of methods consisting of:printing or foil attach or ink jetting or dispensing. Adhesion layer 216may be formed over one or more portions 212 of layer 202 released fromfurther carrier material 208, and chip 218 may be adhered to carrier 204via adhesion layer 216.

In 230 of FIG. 2C, chip attachment may be carried out. Chip attachmentmay be carried out by adhesion, e.g. gluing, soldering. Chip 218including one or more contact pads 222 may be adhered to carrier 204 vialayer 202, e.g. to one or more portions 212 of layer 202 released fromfurther carrier material 202. It may be understood that chip 218 may beadhered to carrier 204 via adhesion layer 216. For example adhesionlayer 216 may adhere chip 218 to layer 202 which may be formed overcarrier 204 and adhered to carrier 204. According to other embodiments,adhesion layer 216 may be formed, e.g. deposited, over a side of chip218 (referred to as the adhered side) to be adhered to layer 202,instead of or in addition to being deposited over one or more portions212. The adhered side may include the back side of chip 218 or frontside of chip 218. FIG. 2C particularly shows that the adhered side mayinclude the back side of chip 218, and one or more contacts pads 222 maybe formed over the front side of chip 218. According to otherembodiments, layer 202, e.g. layer 202C, polyimide, may be the adhesionlayer 216 which adheres chip 218 to layer 202.

Chip 218 may not be limited to having a particular thickness, however,various embodiments may include chip 218 having a thickness ranging fromabout 20 μm to about 250 μm, e.g. about 50 μm to about 150 μm, e.g.about 60 μm to about 100 μm. IC chip 218 to be mounted mayalternatively, or additionally, carry on their back side, a die attachfilm or foil (adhesion layer 216), which may be brought on in advance toa wafer, e.g. a silicon wafer including the IC chips. The larger the ICchips and stronger the metal foil (adhesion 216), the more important itis to utilize a glue, e.g. an adhesive, which may have a smaller Young'smodulus (E) e.g. 3 MPA. If it is a priority to have higher currentdensity, a solder method, e.g. diffusions solder method, or a nanopastemay be used instead of gluing. Therefore, the electrically conductingfoil may be newly arranged after the solder process, and the chips maybe centrally adjusted in the free space, i.e. the cavity.

Method 200 may further include depositing passivation material 224 overcarrier 204 and chip 218 as shown in 240 of FIG. 2D. Passivationmaterial 224 may be formed over layer 202 and/or over further portions214 of layer 202. Passivation material 224 may be formed over furthercarrier material 206. Passivation material 224 may be formed over a sidewhich faces a direction opposite to the direction the adhered sidefaces, e.g. over the front side of chip 218. Passivation material 224may be formed over one or more contact pads 222. Passivation material224 may be formed over one or more sidewalls 226 of chip 218, whereinone or more sidewalls 226 are arranged between chip front side and chipback side, for example, one or more sidewalls 226 may connect chip frontside and chip back side. Passivation material 224 may be formed betweenone or more sidewalls 226 of chip 218 and one or more sidewalls 228 offurther carrier material 206. Passivation material 224 may not belimited to having a particular thickness, but according to variousembodiments may have a thickness ranging from about 10 μm to about 20μm. Passivation material 224 may include at least one material from thefollowing group of materials, the group consisting of: polyimide, epoxy,polymers. Passivation material 224 may be deposited by imide-processingtechniques, e.g. spin coat, e.g. foil lamination, e.g. spray coating.Imide, e.g. polyimide, processing may include die embedding (lastingapproximately 5 seconds), for the package, to enforce high voltageisolation. A die attach tool may be used for height control by cavityedge. Embedded wafer level ball grid array (eWLB) processing may becarried out, for example, ball array (BA) or land grid array (LGA)finishing may be carried out. In other words, the reconstituted wafermay be finished with, e.g. a photosensitive polyimide, and carrier 204,IC chip 218 and the gaps around the IC chip 218 may be filled with thepolyimide. Alternatively a photo-structureable or laser structureablepermanent foil may be used.

Method 200 may further include selectively removing one or more portions232 of passivation material 224 thereby releasing the one or morecontact pads 222 from passivation material 224 as shown in 240. One ormore portions 232 of passivation material 224 may be selectively removedby at least one method from the following group of methods, the group ofmethods consisting of: chemical etching, plasma etching, laserstructuring, photostructuring. It may be understood that one or moreportions 232 may be portions of passivation material 224 formed over,e.g. indirectly on or directly on, one or more contact pads 222.Therefore, passivation material 224 may electrically insulate chip 218from carrier 204, adhesion layer 216, layer 202 and further carriermaterial 206. As shown in FIG. 7, passivation material 224 may includepolyimide which may be used for gap filling, for example to fill gaps754 between one or more sidewalls 226 of chip 218 and one or moresidewalls 228 of further carrier material 206. Gaps 754 are notparticularly limited to having a particular width or height, howeveraccording to various embodiments, gaps 754 may have a width ranging fromabout 30 μm to about 100 μm, e.g. 50 μm to about 80 μm.

After exposure and development, vias to IC chip 218 and possibly vias tocarrier 204 may be freed, e.g. formed. Redistribution lines (RDL) 238,242 may be deposited, e.g. in the vias, like in eWLB, wherein polyimideor other passivation materials 224, may serve as a solder mask.Subsequently, the wafer level package, e.g. the wafer level ball gridarray (WLB) may be provided with solder balls according to design, or asland grid array (LGA). This is shown in 250, wherein electricallyconductive material 234 may be formed over passivation material 224 andover one or more contact pads 222, for example in one or more portions232. In other words, electrically conductive material 234 may be formedover the exposed one or more contact pads 222. Electrically conductivematerial 234 may include at least one material from the following groupof materials, the group consisting of: copper, nickel, iron, silver,gold, palladium, copper alloy, nickel alloy, iron alloy, silver alloy,gold alloy, palladium alloy. Electrically conductive material 234 may bereferred to as a redistribution layer and/or as an electricalinterconnect. Additionally, 240 and 250 may be repeated, e.g. furtherpassivation material 236 may be formed over passivation material 224,one or more portions 238 of further passivation material 236 may beselectively removed, and further electrically conductive material 242may be formed in the one or more selectively removed portions 238 offurther passivation material 236, wherein further electricallyconductive material 242 (further redistribution layers) may be inelectrical connection with electrically conductive material 234. Anynumber of redistribution layers 238, 242 may be formed over chip 218 asrequired, and processes 240 and 250 may be repeated as many times asnecessary to achieve the necessary number of redistribution layers. Afinal passivation layer, e.g. 224 or 236 may be formed over the wholepackage, including chip 218. The final passivation layer serving as asolder mask. One or more portions 244 of electrically conductivematerial, e.g. 234 or 242 may be exposed. These portions of electricallyconductive material may be in electrical connection with one or morecontact pads 222, and may be redistributed, e.g. relocated, from theoriginal location of one or more contact pads 222, e.g. in a fan-in orfan-out configuration. As shown in FIG. 2G, according to variousembodiments, redistribution lines 238, 242 may be formed such that atleast one redistribution line 238, 242 may be arranged outwardly awayfrom the chip, to contact a contact pad 222 to a joining material 246away from the chip. Furthermore, at least one redistribution line 238,242 may be arranged inwardly, e.g. to contact another contact pad 222 toa joining material 246 over the chip. Furthermore, redistribution lines238, 242 may be formed to provide a ground distribution, e.g. between afurther contact pad 222 and carrier 204.

As shown in FIG. 2F, joining material 246 may be added to the exposedone or more portions 244 of electrically conductive material, e.g. 234or 242. Joining material 246 may include at least one from the followinggroup of joining structures, the group consisting of: solder balls andsolder bumps. Joining material 246 may include a solder ball grid array.Joining material 246 may include a solder material from at least onefrom the following group of materials, the group consisting of: silver,lead, zinc, tin, and/or one or more alloys thereof.

Without adding any mold material, the arrangement may be individualized(separating through dicing line 248) to separate each chip package 270from neighboring chip packages, e.g. 270 a. Method 200 may includeindividualizing chip package 270 by separating through carrier 204,further carrier material 206 and layer 202. Chip package 270 may beindividualized by separating, e.g. dicing, through carrier 204, furthercarrier material 206, passivation material, e.g. 224, e.g. 236, andlayer 202.

According to various embodiments, chip package 270, 280 may include:carrier 204; layer 202 formed over carrier 204; further carrier material206 formed over layer 202; one or more portions 212 of layer 202released from further carrier material 206; and chip 218 including oneor more contact pads 222, wherein chip 218 is adhered to carrier 204 vialayer 202.

FIG. 3 shows method 300 for manufacturing a wafer level package. Method300 may include

forming a layer over a carrier (in 310);

forming further carrier material over the layer (in 320);

selectively removing a plurality of portions of the further carriermaterial thereby releasing a plurality of portions of the layer from thefurther carrier material (in 330); and

adhering a plurality of chips including one or more contact pads to thecarrier via the plurality of portions of the layer released from thefurther carrier material; wherein the plurality of chips are commonlyheld by the layer (in 340).

Method 300 may include one or more or all of the features alreadydescribed with respect to method 200. According to an embodiment, Method300 may include a method for manufacturing a wafer level package (forexample, as shown in FIG. 2C), the method including:

forming layer 202 over carrier 204; forming further carrier material 206over layer 202; selectively removing a plurality of portions 208 offurther carrier material 206 thereby releasing a plurality of portions212 of layer 202 from further carrier material 206; adhering a pluralityof chips 218 including one or more contact pads 222 to carrier 204 viaplurality of portions 212 of layer 202 released from further carriermaterial 206; wherein plurality of chips 218 are commonly held by layer202. To be commonly held may be understood to mean that the plurality ofchips 218 may be arranged over the same continuous layer 202. A waferlevel package may be understood to include a plurality of chips held inthe form of a reconstituted wafer. While traditionally a reconstitutedwafer may include a plurality of chips embedded in mold material, awafer level package according to various embodiments may include holdingthe plurality of chips within carrier 202 and/or further carriermaterial 206, without mold material. In other words, a chip package anda wafer level package according to various embodiments may not require amold material as with conventional chip packages.

Various embodiments provide a wafer level package (as shown in FIG. 2C)including carrier 204; layer 202 formed over carrier 204; furthercarrier material 206 formed over layer 202; plurality of portions 212 oflayer 202 released from further carrier material 206; plurality of chips218 each including one or more contact pads 222, wherein plurality ofchips 218 are adhered to carrier 204 via plurality of portions 212 oflayer 202 released from further carrier material 206; wherein pluralityof chips 218 are commonly held by layer 202.

FIG. 4 shows method 400 for manufacturing a chip package according to anembodiment. Method 400 may include:

forming a plurality of cavities within a chip carrier (in 410);

disposing a plurality of chips, each chip including one or more contactpads, in the plurality of cavities (in 420);

depositing passivation material over the chip carrier and the pluralityof chips (in 430);

selectively removing one or more portions of the passivation materialthereby releasing one or more chip contact pads of the plurality ofchips from the passivation material (in 440); and

forming electrically conductive material over the one or more chipcontact pads and over the passivation material (in 450).

Method 400 may include: forming plurality of cavities 208 within chipcarrier 204, 206; disposing plurality of chips 218, each chip 218including one or more contact pads 222, in plurality of cavities 208;depositing passivation material 224 over chip carrier 204, 206 andplurality of chips 218; selectively removing one or more portions 232 ofpassivation material 224 thereby releasing one or more chip contact pads222 of plurality of chips 218 from the passivation material 224; andforming electrically conductive material 234 over one or more chipcontact pads 222 and over passivation material 224.

FIG. 5 shows chip package 510 according to an embodiment. Chip package510 may include: chip carrier e.g. 204 and/or 206 including at least onecavity 208 formed within chip carrier, e.g. 204 and/or 206; at least onechip 218, including one or more contact pads 222, and disposed in the atleast one cavity 208; passivation material 224 formed over chip carriere.g. 204 and/or 206 and at least one chip 218, wherein one or more chipcontact pads 222 of at least one chip 218 are released from passivationmaterial 224; and electrically conductive material 234 formed over oneor more chip contact pads 222, wherein electrically conductive material234 is formed over the passivation material 224.

FIG. 6 shows chip package 610 according to an embodiment. Chip package610 may include one or more or all of the features of chip packages 210,510, except that chip package may not include any joining materials 246,e.g. solder balls, e.g. solder bumps etc. Chip package 610 may thereforeprovide a special low cost variation, wherein the RDL may be omitted,and possibly only the isolator, i.e. passivation material 224, may beapplied, e.g. over carrier 204. Chip package 610 may be implementedparticularly when the dimensions are small and the IC has solder pads.

Selected portions 648 of carrier 204 may be used as an electricalinterconnect without the need for forming passivation materials, e.g.224, e.g. 236, and further redistribution materials e.g. 234, e.g. 242,over selected portions 648 carrier 204. These selected portions 648 mayfor example include a source contact 222S. If chip 218 includes a powersemiconductor chip, adhered side, e.g. back side, may include asource/drain contact 223S, instead of source/drain contact 222S formedover front side of chip 218. A further source/drain contact pad 222D maybe formed on the front side of chip 218. A gate contact pad 222G may beformed on front side of chip 218. Back side source/drain contact 223Smay be electrically connected to carrier 204 via layer 202 and adhesionlayer 216. Therefore, a selected portion 648 of carrier 204 may be usedas a direct electrical interconnect contact 222S to back sidesource/drain contact 223S. This may reduce costs because redistributionlayers e.g. 234, e.g. 242, and passivation material e.g. 224, e.g. 236,may not be needed for forming a further joining structure interconnect244, e.g. a solder ball, to the back side source/drain contact 223S.Redistribution layers e.g. 234, e.g. 242, and passivation material e.g.224, e.g. 236, for the front side source/drain contact 222D and frontside gate contact 222G, and joining structures 246 (not shown in FIG. 6)electrically connected to front side source/drain contact 222D and frontside gate contact 222G may be formed as described according to previousembodiments. Passivation material 652 may be formed over one or moresidewalls of carrier 204 and/or further carrier material 206, whereinpassivation material 652 may be used to enforce high voltage (HV)isolation. Chip package 610 may include a low cost, relatively smalleWLB chip package for power applications.

It may be understood that according to various embodiments, each chippackage, e.g. chip package 270, e.g. chip package 510, e.g. chip package610, may not be limited to including only one chip. For example, a chippackage according to an embodiment may include a half-bridge chiparrangement. Therefore, each chip package, after individualization, e.g.dicing, may include a plurality of, e.g. two, portions 212, of layer 202released from further carrier material 206; plurality of chips 218, e.g.two chips, which may for example, be arranged in half-bridgearrangement, each chip 218 including one or more contact pads 222, e.g.222S, e.g. 222D, wherein chips 218 may be adhered to carrier 204 viaportions 212 of layer 202 released from further carrier material 206;wherein chips 218 are commonly held by layer 202.

Various embodiments provide a method for manufacturing a chip packageand/or wafer level package which is reliable and 175° C. compatible,i.e. process compatible at 175° C. The chip package and wafer levelpackage according to various embodiments may exhibit low thermalresistance. Various embodiments provide a method for manufacturing achip package and/or wafer level package which is eWLB front end (FE)compatible. Various embodiments provide a method for manufacturing achip package and/or wafer level package wherein an integrated circuit(IC) with a high current backside contact is provided.

Various embodiments provide a method for manufacturing a chip package,the method including: forming a layer over a carrier; forming furthercarrier material over the layer; selectively removing one or moreportions of the further carrier material thereby releasing one or moreportions of the layer from the further carrier material; adhering a chipincluding one or more contact pads to the carrier via the layer.

According to an embodiment, the carrier includes an electricallyconductive sheet.

According to an embodiment, the carrier includes at least one materialfrom the following group of materials, the group consisting of: copper,nickel, iron, silver, gold, palladium, copper alloy, nickel alloy, ironalloy, silver alloy, gold alloy, palladium alloy.

According to an embodiment, the carrier includes a thickness rangingfrom about 50 μm to about 1000 μm.

According to an embodiment, the layer includes an electricallyconductive material including at least one material from the followinggroup of materials, the group consisting of: silver, silver alloy, gold,gold alloy, nickel, palladium.

According to an embodiment, forming a layer over the carrier includesforming the layer over the carrier by at least one method from thefollowing group of methods, the group of methods consisting of:electroplating, electroless plating, galvanic deposition, lamination,foil lamination, sputtering, evaporation, chemical vapor deposition,plasma enhanced chemical vapor deposition, printing.

According to an embodiment, forming a layer over the carrier includesforming an electrically conductive layer including at least one of anelectrically conductive glue and an electrically conductive nanopaste.

According to an embodiment, forming a layer over the carrier includesforming an electrically conductive layer over the carrier and asintering layer over the electrically conductive layer.

According to an embodiment, forming a layer over the carrier includesforming at least one of an electrically conductive layer and anelectrically insulating layer over the carrier.

According to an embodiment, the electrically insulating layer includesan electrically insulating adhesive including at least one from thefollowing group of materials, the group consisting of: polyimide,benzocyclobuten, epoxy.

According to an embodiment, the further carrier material includes athickness ranging from about 60 μm to about 200 μm.

According to an embodiment, the further carrier material includes thesame material as the carrier.

According to an embodiment, forming further carrier material over thelayer includes forming further carrier material over the layer by atleast one method from the following group of methods, the group ofmethods consisting of: lamination, sintering, gluing.

According to an embodiment, forming a layer over a carrier and formingfurther carrier material over the layer includes adhering a foilincluding the layer and further carrier material to the carrier.

According to an embodiment, selectively removing one or more portions ofthe further carrier material thereby releasing one or more portions ofthe layer from the further carrier material includes selectively etchingone or more portions of the further carrier material wherein the layerfunctions as an etch stop layer.

According to an embodiment, selectively removing one or more portions ofthe further carrier material thereby releasing one or more portions ofthe layer from the further carrier material includes selectively etchingone or more portions of the further carrier material wherein the layerprevents etching of the carrier.

According to an embodiment, selectively removing one or more portions ofthe further carrier material thereby releasing one or more portions ofthe layer from the further carrier material includes selectivelyremoving one or more portions of the further carrier material by atleast one method from the following group of methods, the group ofmethods consisting of: chemical etching, plasma etching, sandblasting.

According to an embodiment, the one or more portions of the layerreleased from the further carrier material are commonly joined byfurther portions of the layer covered by the further carrier material.

According to an embodiment, adhering a chip including one or morecontact pads to the carrier via the layer includes adhering the chipincluding one or more contact pads to the carrier via one or moreportions of the layer released from the further carrier material.

According to an embodiment, the method further includes forming anadhesion layer over the one or more portions of the layer released fromthe further carrier material, and adhering the chip to the carrier viathe adhesion layer.

According to an embodiment, the adhesion layer includes an electricallyconductive material including at least one material from the followinggroup of materials, the group consisting of: an electrically conductiveglue, an electrically conductive adhesive, an electrically conductivepolymer, an electrically conductive organic polymer, an electricallyconductive epoxy.

According to an embodiment, the adhesion layer includes an electricallyinsulating material including at least one material from the followinggroup of materials, the group consisting of: a polymer, an organicpolymer, epoxy.

According to an embodiment, the adhesion layer includes at least one ofan electrically conductive glue and an electrically conductivenanopaste.

According to an embodiment, the adhesion layer includes a thicknessranging from about 3 μm to about 70 μm.

According to an embodiment, the method further includes depositingpassivation material over the carrier and the chip; and selectivelyremoving one or more portions of the passivation material therebyreleasing the one or more contact pads from the passivation material.

According to an embodiment, the method further includes depositingpassivation material over the layer.

According to an embodiment, the method further includes formingelectrically conductive material over the passivation material and overthe one or more contact pads.

According to an embodiment, the method further includes individualizinga chip package by separating through the carrier, the further carriermaterial and the layer.

According to an embodiment, forming a layer over the carrier includesforming an electrically insulating layer over the carrier; and themethod further includes selectively removing one or more portions of atleast one of the carrier and the further carrier material, wherein atleast one of the carrier and the further carrier material includes anelectrically conductive redistribution layer.

Various embodiments provide a chip package, including: a carrier; alayer formed over the carrier; further carrier material formed over thelayer; one or more portions of the layer released from the furthercarrier material; a chip including one or more contact pads, wherein thechip is adhered to the carrier via the layer.

Various embodiments provide a method for manufacturing a wafer levelpackage, the method including forming a layer over a carrier; formingfurther carrier material over the layer; selectively removing aplurality of portions of the further carrier material thereby releasinga plurality of portions of the layer from the further carrier material;adhering a plurality of chips including one or more contact pads to thecarrier via the plurality of portions of the layer released from thefurther carrier material; wherein the plurality of chips are commonlyheld by the layer.

Various embodiments provide a wafer level package including a carrier; alayer formed over the carrier; further carrier material formed over thelayer; a plurality of portions of the layer released from the furthercarrier material; a plurality of chips each including one or morecontact pads, wherein the plurality of chips are adhered to the carriervia the plurality of portions of the layer released from the furthercarrier material; wherein the plurality of chips are commonly held bythe layer.

While the invention has been particularly shown and described withreference to specific embodiments, it should be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. The scope of the invention is thusindicated by the appended claims and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced.

What is claimed is:
 1. A method for manufacturing a chip package, themethod comprising forming a layer over a carrier; forming furthercarrier material over the layer; selectively removing one or moreportions of the further carrier material thereby releasing one or moreportions of the layer from the further carrier material; and adhering achip comprising one or more contact pads to the carrier via the layer;wherein forming a layer over a carrier and forming further carriermaterial over the layer comprises adhering a foil comprising the layerand further carrier material to the carrier.
 2. The method according toclaim 1, wherein the carrier comprises an electrically conductive sheet.3. The method according to claim 1, wherein the carrier comprises atleast one material from the following group of materials, the groupconsisting of: copper, nickel, iron, silver, gold, palladium, copperalloy, nickel alloy, iron alloy, silver alloy, gold alloy, palladiumalloy.
 4. The method according to claim 1, wherein the carrier comprisesa thickness ranging from about 50 μm to about 1000 μm.
 5. The methodaccording to claim 1, wherein the layer comprises an electricallyconductive material comprising at least one material from the followinggroup of materials, the group consisting of: silver, silver alloy, gold,gold alloy, nickel, palladium.
 6. The method according to claim 1,wherein forming a layer over the carrier comprises forming the layerover the carrier by at least one method from the following group ofmethods, the group of methods consisting of: electroplating, electrolessplating, galvanic deposition, lamination, foil lamination, sputtering,evaporation, chemical vapor deposition, plasma enhanced chemical vapordeposition, printing.
 7. The method according to claim 1, whereinforming a layer over the carrier comprises forming an electricallyconductive layer comprising at least one of an electrically conductiveglue and an electrically conductive nanopaste.
 8. The method accordingto claim 1, wherein forming a layer over the carrier comprises formingan electrically conductive layer over the carrier and a sintering layerover the electrically conductive layer.
 9. The method according to claim1, wherein forming a layer over the carrier comprises forming at leastone of an electrically conductive layer and an electrically insulatinglayer over the carrier.
 10. The method according to claim 9, wherein theelectrically insulating layer comprises an electrically insulatingadhesive comprising at least one from the following group of materials,the group consisting of: polyimide, benzocyclobuten, epoxy.
 11. Themethod according to claim 1, wherein the further carrier materialcomprises a thickness ranging from about 60 μm to about 200 μm.
 12. Themethod according to claim 1, wherein the further carrier materialcomprises the same material as the carrier.
 13. The method according toclaim 1, wherein forming further carrier material over the layercomprises forming further carrier material over the layer by at leastone method from the following group of methods, the group of methodsconsisting of: lamination, sintering, gluing.
 14. The method accordingto claim 1, wherein selectively removing one or more portions of thefurther carrier material thereby releasing one or more portions of thelayer from the further carrier material comprises selectively etchingone or more portions of the further carrier material wherein the layerfunctions as an etch stop layer.
 15. The method according to claim 1,wherein selectively removing one or more portions of the further carriermaterial thereby releasing one or more portions of the layer from thefurther carrier material comprises selectively etching one or moreportions of the further carrier material wherein the layer preventsetching of the carrier.
 16. The method according to claim 1, whereinselectively removing one or more portions of the further carriermaterial thereby releasing one or more portions of the layer from thefurther carrier material comprises selectively removing one or moreportions of the further carrier material by at least one method from thefollowing group of methods, the group of methods consisting of: chemicaletching, plasma etching, sandblasting.
 17. The method according to claim1, wherein the one or more portions of the layer released from thefurther carrier material are commonly joined by further portions of thelayer covered by the further carrier material.
 18. The method accordingto claim 1, wherein adhering a chip comprising one or more contact padsto the carrier via the layer comprises adhering the chip comprising oneor more contact pads to the carrier via one or more portions of thelayer released from the further carrier material.
 19. A method formanufacturing a chip package, the method comprising forming a layer overa carrier; forming further carrier material over the layer; selectivelyremoving one or more portions of the further carrier material therebyreleasing one or more portions of the layer from the further carriermaterial; and adhering a chip comprising one or more contact pads to thecarrier via the layer; forming an adhesion layer over the one or moreportions of the layer released from the further carrier material, andadhering the chip to the carrier via the adhesion layer.
 20. The methodaccording to claim 19, wherein the adhesion layer comprises anelectrically conductive material comprising at least one material fromthe following group of materials, the group consisting of: anelectrically conductive glue, an electrically conductive adhesive, anelectrically conductive polymer, an electrically conductive organicpolymer, an electrically conductive epoxy.
 21. The method according toclaim 19, wherein the adhesion layer comprises an electricallyinsulating material comprising at least one material from the followinggroup of materials, the group consisting of: a polymer, an organicpolymer, epoxy.
 22. The method according to claim 19, wherein theadhesion layer comprises at least one of an electrically conductive glueand an electrically conductive nanopaste.
 23. The method according toclaim 19, wherein the adhesion layer comprises a thickness ranging fromabout 3 μm to about 70 μm.
 24. A method for manufacturing a chippackage, the method comprising forming a layer over a carrier; formingfurther carrier material over the layer; selectively removing one ormore portions of the further carrier material thereby releasing one ormore portions of the layer from the further carrier material; andadhering a chip comprising one or more contact pads to the carrier viathe layer; depositing passivation material over the carrier and thechip; and selectively removing one or more portions of the passivationmaterial thereby releasing the one or more contact pads from thepassivation material.
 25. The method according to claim 24, furthercomprising depositing passivation material over the layer.
 26. Themethod according to claim 25, further comprising forming electricallyconductive material over the passivation material and over the one ormore contact pads.
 27. The method according to claim 1, furthercomprising individualizing a chip package by separating through thecarrier, the further carrier material and the layer.
 28. The methodaccording to claim 1, wherein forming a layer over the carrier comprisesforming an electrically insulating layer over the carrier; and themethod further comprising selectively removing one or more portions ofat least one of the carrier and the further carrier material, wherein atleast one of the carrier and the further carrier material comprises anelectrically conductive redistribution layer.
 29. A method formanufacturing a wafer level package, the method comprising forming alayer over a carrier; forming further carrier material over the layer;selectively removing a plurality of portions of the further carriermaterial thereby releasing a plurality of portions of the layer from thefurther carrier material; adhering a plurality of chips comprising oneor more contact pads to the carrier via the plurality of portions of thelayer released from the further carrier material; wherein the pluralityof chips are commonly held by the layer; and wherein forming a layerover a carrier and forming further carrier material over the layercomprises adhering a foil comprising the layer and further carriermaterial to the carrier.